Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2019

Qualified Pension Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Components of Net Periodic Pension Costs

The following tables include the components of net periodic pension costs for qualified pension plans.

	Three Months Ended June 30, 2019
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	37		$	12		$	10		$	6		$	6		$	1		$	2		$	2
Interest cost on projected benefit obligation	82			21			26			12			13			4			7			3
Expected return on plan assets	(143		)	(37		)	(45		)	(21		)	(22		)	(6		)	(10		)	(6		)
Amortization of actuarial loss	25			5			9			3			6			—			1			1
Amortization of prior service credit	(8		)	(2		)	—			(1		)	(1		)	—			(1		)	(2		)
Net periodic pension costs	$	(7	)	$	(1	)	$	—		$	(1	)	$	2		$	(1	)	$	(1	)	$	(2	)

	Three Months Ended June 30, 2018
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	45		$	15		$	13		$	8		$	6		$	1		$	3		$	2
Interest cost on projected benefit obligation	75			18			22			10			12			4			6			3
Expected return on plan assets	(140		)	(37		)	(43		)	(21		)	(23		)	(7		)	(11		)	(6		)
Amortization of actuarial loss	33			7			11			5			6			1			2			3
Amortization of prior service credit	(8		)	(2		)	(1		)	(1		)	(1		)	—			—			(3		)
Net periodic pension costs	$	5		$	1		$	2		$	1		$	—		$	(1	)	$	—		$	(1	)

	Six Months Ended June 30, 2019
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	74		$	24		$	21		$	12		$	10		$	2		$	4		$	3
Interest cost on projected benefit obligation	165			41			52			24			27			9			13			6
Expected return on plan assets	(286		)	(75		)	(89		)	(44		)	(44		)	(14		)	(21		)	(11		)
Amortization of actuarial loss	49			11			18			6			12			1			3			3
Amortization of prior service credit	(16		)	(4		)	(1		)	(1		)	(1		)	—			(1		)	(5		)
Net periodic pension costs	$	(14	)	$	(3	)	$	1		$	(3	)	$	4		$	(2	)	$	(2	)	$	(4	)

	Six Months Ended June 30, 2018
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	90		$	30		$	26		$	15		$	11		$	2		$	5		$	4
Interest cost on projected benefit obligation	150			36			46			21			25			9			12			6
Expected return on plan assets	(280		)	(74		)	(88		)	(42		)	(46		)	(14		)	(21		)	(12		)
Amortization of actuarial loss	66			14			22			10			12			2			4			6
Amortization of prior service credit	(16		)	(4		)	(2		)	(1		)	(1		)	—			—			(6		)
Net periodic pension costs	$	10		$	2		$	4		$	3		$	1		$	(1	)	$	—		$	(2	)